Growth kinetics and structural perfection of (InN)1/(GaN)1-20 short-period superlattices on plus c-GaN template in dynamic atomic layer epitaxy

The growth kinetics and structural perfection of (InN)(1)/(GaN)(1-20) short-period superlattices (SPSs) were investigated with their application to ordered alloys in mind. The SPSs were grown on +c-GaN template at 650 degrees C by dynamic atomic layer epitaxy in conventional plasma-assisted molecular beam epitaxy. It was found that coherent structured InN/GaN SPSs could be fabricated when the thickness of the GaN barrier was 4ML or above. Below 3ML, the formation of SPSs was quite difficult owing to the increased strain in the SPS structure caused by the use of GaN as a template. The effective or average In composition of the (InN)(1)/(GaN)(4) SPSs was around 10%, and the corresponding InN coverage in the similar to 1ML-thick InN wells was 50%. It was found that the effective InN coverage in similar to 1ML-thick InN wells could be varied with the growth conditions. In fact, the effective In composition could be increased up to 13.5%, i. e., the corresponding effective InN coverage was about 68%, by improving the capping/freezing speed by increasing the growth rate of the GaN barrier layer. Published by AIP Publishing.